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Daytime Planet Observation

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#1 TCW

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Posted 18 August 2014 - 01:01 AM

Recently I was able to view Mercury, Venus and Jupiter during daylight but was not able to find Mars and Saturn.  I used a 4 "refractor at 40x with an AVX mount. Has anyone had luck finding these two planets and if so can you share any tips?


Edited by TCW, 18 August 2014 - 01:01 AM.

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#2 and75

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Posted 18 August 2014 - 06:56 AM

Yes, I saw both of them with my previous 4" apo, but needed a helping object: a brighter planet or Moon. I saw Mars minutes before Moon occulted in 2008 at daylight, and Saturn near Venus later.

 

Use a planetarium software to find a close conjunction with Moon or Venus.

And internal baffling is critical to block the reflection of sunlight. Even sunlight reflecting from the edge of the lens cell is very disturbing.



#3 TCW

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Posted 18 August 2014 - 03:20 PM

Jupiter had very little contrast with the sky and was invisible when the focus was off even a tiny bit.


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#4 jgraham

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Posted 18 August 2014 - 07:53 PM

I've been able to see planets and stars as faint as magnitude 3ish with my 6" f/8 achromat. The trick for me is to have a spot accurately marked where my tripod goes so when I set it out in daylight the polar alignment is fairly good. I synch my mount on the sun and from there my GoTos are fairly good.



#5 TCW

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Posted 18 August 2014 - 08:54 PM

I aligned on the sun using a solar filter and then found and synced to Venus. After that Mercury and Jupiter were fairly easy.



#6 September

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Posted 29 September 2014 - 11:56 AM

I was amazed when I just read an article that you can actually observe during daylight :shocked: You can actually see more than night observation in some brightly lit cities with the unaided eye! Wow. Who knew?? Learning more amazing things every day :)



#7 DavidOrDave

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Posted 01 October 2017 - 10:10 PM

Today - October 1, 2017 I was able to view Venus, Mercury, Mars, and Jupiter in the bright clear midday sun (and spot three sunspot groups). Using my CPC-800. I thought it was pretty cool to view four planets by day. Jupiter was pretty low contrast and I had no luck spotting Saturn.

 

I solar aligned to the sun, then slewed to Venus and used "Alignment stars" to replace the unassigned slot. Then back to the Sun, and onto Mercury and iterated back to Venus to get good goto accuracy. Then I could slew to Mars and Jupiter.

 

 

 



#8 Tony Flanders

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Posted 02 October 2017 - 04:01 AM

Venus is easy to see naked-eye during the day, and Mercury too under the right conditions. Jupiter is considerably harder, but definitely possible when the sky is nice and transparent. That makes it easy to sight on these planets with a regular finder.

 

I doubt that Saturn is visible naked-eye, except immediately before sunset or after sunrise. Mars presumably is at opposition, when it can sometimes be brighter than Jupiter. Moreover, Mars's red should show better against a blue sky than Jupiter's bluish disk. I have seen Saturn and Mars during the daytime during lunar occultations, but not otherwise.

 

Given the correct timing, almost anything can be observed in the early morning simply by finding it before sunrise and continuing to track it through sunrise and beyond. This works for stars down to magnitude 2, and no doubt fainter in good conditions.

 

A Go To scope well aligned the previous night and then left undisturbed should be able to locate things well the next day.

 

Likewise, a well-aligned high-quality equatorial mount with a properly calibrated RA dial should be able to find things during the day using setting circles.



#9 Loren Gibson

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Posted 02 October 2017 - 07:29 AM

Daytime sighting of planets is definitely possible but often difficult (as you have found), and Mars and Saturn are harder to detect against the bright sky background than Jupiter and Venus. I suspect that it doesn't take too much haze or other aerosols to reduce the contrast between planet and sky to the point of invisibility. This also makes it more difficult to see them for a given elongation “near” the Sun.

 

Depending upon how recently you attempted Mars, it may have been too close to the Sun to see against the brighter background sky near to the Sun. When did your attempt occur? I've seen Mars at 69 degrees elongation in daylight through an 89 mm aperture Questar, easily enough that I think it can be seen at somewhat closer elongations under good conditions. However, Mars was only 12 degrees elongation at the beginning of September, growing to 22 degrees elongation at the beginning of this month. By comparison, my closest sighting of Jupiter was 17 degrees elongation under somewhat mediocre sky clarity through my 90 mm apochromat, and it was rather difficult to see at that (and not visible at all in my Meade 90 mm ETX). Based on my experience, I'd bet that Mars may be impossible to detect at these small elongations, although I'd be delighted to be corrected by someone who has detected Mars this close to the Sun, perhaps at a site with excellent sky conditions.

 

Assuming you're able to point the telescope to the correct location (and your success in finding the others suggests that you can), be patient. Keep trying Mars, as its elongation will grow as we approach the next opposition, and you'll stumble on the day when sky conditions are excellent and it's far enough from the Sun to be detected.

 

Saturn may also be getting too close to be seen. I've seen it at about 90 degrees elongation, and it was not exactly a dazzling sight! It's a little over 70 degrees elongation right now. I tried once a couple of years ago when it was 75 degrees elongation and failed to see it. I don't know if it was inherently too close to be reliably detected, or maybe the sky conditions weren't optimal, but in any event I failed to see it.

 

One thing that is sometimes helpful,though not always, is the use of a single polarizing filter. I brought it up in a thread in the Solar System Observing forum. There's a link in that thread, near the end, to a previous thread about another observer's success with a single polarizing filter as well.

 

Hope this is helpful.

 

Loren



#10 Loren Gibson

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Posted 02 October 2017 - 07:34 AM

Jupiter had very little contrast with the sky and was invisible when the focus was off even a tiny bit.

Oh, and Jupiter is only 20-ish degrees elongation right now. You bagged it anyway, excellent! I observed the same traits you describe when I saw it at 17 degrees elongation.

 

Loren



#11 Keith

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Posted 09 October 2017 - 02:55 AM

With an extremely rough polar alignment (bore sight of Polaris, no polar scope), cg5 with an orion true track RA drive, I tracked Venus into the afternoon after my last session in the desert with televue 101. Next time I am out I plan on setting it on mars with my 8" Meade ARC (lx200r) OTA on the cg5. I will fine tune my collimation during the night and hopefully be able to see good detail at high power.

At times like these I regret selling things like my modified baby nexstar mount with upgraded sky align hand controller, and my advanced GT mount. Keeping the GM8 would have helped, I'm sure the old Gemini could do it as well. The G11 is too unwieldy for me in my current livng and vehicle situation so it lives in storage. I sold the gm8 during a much needed downsizing though, which left me just the manual cg5 as my only compact gem. The GM8 wasn't much larger and I would be using it now if I didn't have to sell it :(

But as long as I pick a planet at dawn, I can track it with my cg5 :)

#12 Dave Mitsky

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Posted 09 October 2017 - 03:40 PM

There's an article on daytime observing posted at https://www.skysurfer.eu/daystars.php

 

Dave Mitsky


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#13 Keith Rivich

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Posted 09 October 2017 - 04:58 PM

Great observation! 

 

At multi day star parties daytime planets and bright stars are always on my observing list. I find them manually using nothing but a compass direction and an angle finder. Here is what I do:

 

With the 18" (tracking platform), at the end of my observing night, I put in my 35 Panoptic and focus (this is THE most important step!). I also verify focus and alignment on my finder. I then point it at Polaris and shut off the platform and go to bed (no covers so as to not accidentally move the finder). I use a rock or a small stick to mark one of the corners of my mirror box so I can register back to north if need be. Using Megastar I get the alt-az and go for it by eyeballing the azimuth (with my stick/rock as a reference) and using the angle finder for the altitude. I go with the brightest of the planets/stars to get warmed up and to also verify my coordinates are accurate. It's a big bummer to hunt and hunt only to find out the program is using a fixed time instead of the PC clock! 

 

On my 25" I do the above except I leave the tracking running after settling on Polaris. 

 

Focus is the most important thing. Just a little bit out will render the object all but invisible against the daytime sky.

Have a reference point you can go back to. 

Practice at night. I find that angle finders aren't all that accurate but they are repeatable.

Point your scope at the proper altitude then pan in azimuth to try and find your target. Altitude is much easier to point to accurately. 

Verify your source for the coordinates are spot on. Don't want to be chasing empty sky.

Find a bright object first to verify all of your gears are meshing.

Did I mention focus. waytogo.gif

 

 Many years ago I found all of the classic planets and around 15 stars, during the day, over the course of a few days.  On one of the nights I observed Uranus, Neptune and Pluto to round off a "all the planets" in one day observing challenge.


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#14 t_image

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Posted 11 October 2017 - 11:23 AM

Question for the veterans,

(and thanks for the tip on focus--slightly intuitive but didn't consider it could be such a negative force multiplier to make things difficult!)

 

Besides elongation,

as Loren mentioned that can greatly help the situation if the factors are available,

has anyone noticed a correlation with how high in the sky the Sun is and degree of difficulty beyond the obvious?

(Obviously post-dawn and pre-dusk are more useful),

but I seemed to notice there is some point at which the Sun reaches a point of altitude that illuminates so much of the dome of the atmosphere that makes the task considerably more difficult.

(especially w/o computerized go-to)....

thoughts?



#15 Loren Gibson

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Posted 24 October 2017 - 07:11 AM

Question for the veterans,

(and thanks for the tip on focus--slightly intuitive but didn't consider it could be such a negative force multiplier to make things difficult!)

 

Besides elongation,

as Loren mentioned that can greatly help the situation if the factors are available,

has anyone noticed a correlation with how high in the sky the Sun is and degree of difficulty beyond the obvious?

(Obviously post-dawn and pre-dusk are more useful),

but I seemed to notice there is some point at which the Sun reaches a point of altitude that illuminates so much of the dome of the atmosphere that makes the task considerably more difficult.

(especially w/o computerized go-to)....

thoughts?

 

I can't definitively answer this question from experience, as I haven't taken the time to view an object during daylight for (say) several hours while the sun's altitude changes by a large amount. Experimenting like this would probably be the best way to answer the question about how much the sun's altitude affects the sky brightness and contrast of objects against the daytime sky.

 

However, I have observed with the sun near the meridian and within an hour of sunrise/sunset, and positions in between. I agree with your own instincts and observation, that when the sun is more than an hour or two after sunrise and before sunset, the whole sky is brighter. When the sun is relatively low, light is attenuated by traveling through more atmosphere before reaching (for example) aerosol particles in the atmosphere above you and on the other side of the sky from the sun.

 

I once used setting circles on my Questar standard to find 3.4 mag. eta Orionis 1/2 hour prior to sunset, and it was near the meridian at the time. It was plain to see, though certainly not dramatically bright, and I bet that I would not have detected it if I tried that 2 or 3 hours before sunset.

 

Loren



#16 Keith Rivich

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Posted 24 October 2017 - 08:55 AM

Question for the veterans,

(and thanks for the tip on focus--slightly intuitive but didn't consider it could be such a negative force multiplier to make things difficult!)

 

Besides elongation,

as Loren mentioned that can greatly help the situation if the factors are available,

has anyone noticed a correlation with how high in the sky the Sun is and degree of difficulty beyond the obvious?

(Obviously post-dawn and pre-dusk are more useful),

but I seemed to notice there is some point at which the Sun reaches a point of altitude that illuminates so much of the dome of the atmosphere that makes the task considerably more difficult.

(especially w/o computerized go-to)....

thoughts?

I never really noticed any difference as far as where the sun is in altitude. Once the sky is bright its bright. As you noted elongation is very important but what is equally important is transparency. Any haze during the day will effectively hide most objects. Another concern is glare from the sun. Make sure you shield your focuser (inside the telescope) and mirrors from the suns glare. I have seen Mercury within 10 degrees of the sun on really clear, steady days.


Edited by Keith Rivich, 24 October 2017 - 09:30 AM.

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